Detailed Instructions: You are given a sentence and a question in the input. The information provided in the sentence should be enough to answer the question. You're expected to write the correct answer. Do not use any facts other than those provided in the sentence.
Q: Sentence: On the other hand , `` Happy '' is a young idealist who volunteers after his friend is killed by fanatical fellow prisoners for voicing doubts about the war 's outcome . 
Question: Whose student volunteered for espionage after his friend is killed by fanatical fellow prisoners?
A:
Happy.